To vanish completely like clouds and mist; a four-character idiom used literally or figuratively for something disappearing without a trace.
告発の証拠は翌朝までに雲散霧消した。
The evidence of the accusation had vanished without a trace by the next morning.
彼の自信は批判を受けて雲散霧消した。
His confidence evaporated when he received criticism.